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Biomedical subjects

R C Bell

Publications and source records attributed to R C Bell.

At least 55 records · Page 3Linked to original sources
PubMed1989

Clinical determinants of abnormalities in pulmonary functions in survivors of the adult respiratory distress syndrome.

Pulmonary function tests (PFTs) were performed in 39 survivors of the adult respiratory distress syndrome (ARDS) in whom clinical data had been prospectively collected during the acute episode. PFTs stabilized within 6 months of the episode and had returned to normal in most survivors. Persistent abnormalities were found after 6 months in diffusing capacity (14 of 23 patients, 61%), vital capacity (10 of 23 patients, 43%), and total lung capacity (five of 24 patients, 21%). To clarify the mechanisms underlying these persistent abnormalities, we attempted to correlate long-term PFT outcomes with estimates of the severity of initial lung injury as assessed from clinical data and with other features of the patient's course. The severity of lung function impairment during the first 3 days of ARDS was not related to long-term PFT values. However, a lower DLCO was related to a higher AaDO2, higher pulmonary artery pressure, and worse radiographic appearance on Days 4 through 7 and to the occurrence of sepsis. A lower FVC was related to higher pulmonary vascular resistance in Days 4 through 7 of ARDS. Long-term values for FVC and TLC were directly related to increasing levels of PEEP applied from Days 4 through 7 of ARDS in patients with peak airway pressures less than 50 cm H2O. Long-term abnormalities of pulmonary function of survivors of ARDS were not related to initial lung impairment but were directly related to persistence of impaired lung function during the acute episode. Recovery of lung function may also have been directly related to therapeutic modalities such as PEEP and impaired by the occurrence of sepsis.

Adolescent↗
PubMed1988

C-reactive protein, leukocytes, and fever after central IL 1 and alpha-MSH in aged rabbits.

Aged and young unanesthetized rabbits with intracerebroventricular cannulas were tested in experiments designed to determine whether increases in plasma C-reactive protein (CRP) level and leukocytosis can be rapidly induced by central administration of crude buffy-coat supernatant commonly called endogenous pyrogen or interleukin 1 (IL 1). The results indicate that both acute-phase responses occur during fever caused by central administration of this supernatant and that they are generally detectable within 2 h. Although the febrile response was smaller in aged female rabbits, there was no decline in CRP or leukocyte responses, an observation that was not predicted. The antipyretic neuropeptide alpha-melanocyte-stimulating hormone (alpha-MSH) reduced fever caused by central IL 1 more effectively in the aged rabbits. alpha-MSH likewise inhibited the CRP and leukocyte responses to central IL 1. The results confirm that CRP and leukocyte responses can be driven by a central IL 1 signal and further indicate that the response can occur rapidly, consistent with direct central nervous system control of the acute-phase responses. The findings indicate that the acute-phase responses depend in part on the age of the host and that the responses can be modulated by an endogenous central nervous system peptide with known antipyretic and immune modulatory properties.

Acute-Phase Reaction↗
PubMed1987

Pulsatile release of antipyretic neuropeptide alpha-MSH from septum of rabbit during fever.

The effects on fever of central administration of alpha-melanocyte-stimulating hormone (alpha-MSH) and its antiserum, the specific increase in central concentration of alpha-MSH during fever, and related results indicate that this neuropeptide is important to central nervous system (CNS) regulation of the febrile response. The present experiments were designed to establish whether alpha-MSH is released from septal tissue during fever and, if so, in what temporal course relative to the febrile response. alpha-MSH release at localized push-pull perfusion sites within the septum during fever induced by intravenous interlukin-1 occurred in two basic patterns: prolonged or repeated release over sequential 10-min sample periods or a more discrete pulse largely confined to a single 10-min period. The greatest increases in concentration and the greatest number of increases occurred during the chill phase of fever, when temperature was rising rapidly, rather than during the plateau phase. Such episodic release is similar to that known to occur in neuroendocrine and other physiological systems, and it provides further support for a physiological role of alpha-MSH in CNS control of fever.

Animals↗
PubMed1986

Incidence, site, and outcome of infections in patients with the adult respiratory distress syndrome.

Bacterial infection in the adult respiratory distress syndrome (ARDS) is associated with the occurrence of multiple organ failures and death. We studied 108 infections in 129 patients with ARDS and evaluated the organisms responsible, the body sites involved, and the outcomes of therapy. Gram-negative bacilli represented 57% of the microbial pathogens and gram-positive cocci 36%. Only 7% of infections were caused by other organisms (fungi, viruses, Pneumocystis, Legionella). Gram-negative organisms were more common in the lung, abdomen, and pleura. Bacteremia was more common in abdominal infections (11 of 17, 67%) than in infections at other sites (18 of 65, 28%), (p less than 0.01); ;9 patients were bacteremic from clinically undetected sites. Ten of 17 (59%) patients with abdominal infections survived compared with 7 of 56 (13%) patients with lung infections (p less than 0.001). A retrospective review of in vitro organism susceptibility and the antibiotics administered revealed that the patients who received adequate antibiotic therapy did not have a higher survival rate (20 of 69, 29%) than those who received inadequate antibiotic therapy (3 of 13, 23%). These data suggest that further investigation of infections in patients with ARDS is required and that emphasis should be placed on pathogenesis, prevention, and host responses.

Adult↗
PubMed1986

The effect of almitrine bismesylate on hypoxemia in chronic obstructive pulmonary disease.

Almitrine bismesylate was studied for its effects on hypoxemia in 67 patients with chronic obstructive lung disease in a placebo-controlled, double-blind study. Arterial Po2 rose by 11.2 mm Hg (p less than 0.05) in 21 patients receiving 100 mg twice daily and by 6.0 mm Hg (p less than 0.05) in 22 patients receiving 50 mg twice daily. Arterial Pco2 decreased by 3.8 mm Hg (p less than 0.05) in the group receiving 100 mg twice daily but was unchanged in patients receiving 50 mg twice daily. Lung function was unaltered except for a slight increase in forced mid-expiratory flow in both dosage groups (p less than 0.05). The major side effect was the unexplained worsening of dyspnea, which occurred in 4 patients (19%) receiving 100 mg twice daily, 2 (9%) receiving 50 mg twice daily group, and 1 (4%) receiving placebo. Almitrine bismesylate improves arterial blood gas values in patients with chronic obstructive lung disease, apparently by reducing intrapulmonary ventilation-perfusion mismatching, and appears to be useful in the long-term management of these patients.

Adult↗
PubMed1986

Monocyte factors modulate in vitro T-lymphocyte mitogenesis in protein malnutrition.

This study investigated changes in T-lymphocyte mitogenesis and immunoregulatory cytokines during protein malnutrition. In vitro T cell response to concanavalin A was compared among protein deprived (PD), energy restricted pair fed control (PF), and ad libitum control (C) rabbits. Cell cultures were supplemented with crude monocyte supernatants (CMS) from PD, PF or C animals at either 1% or 8% final concentration in culture. Prostaglandin E2 (PGE2) concentration of unstimulated or stimulated lymphocyte culture supernatants and CMS was determined. Lymphocyte cultures from PD, PF and C animals had enhanced 3H-thymidine incorporation when supplemented with C and/or PF derived CMS. Addition of 8% CMS from PD rabbits inhibited proliferation below levels observed in mitogen-only stimulated groups in all cultures. At the 1% concentration, inhibition was seen in PD and C derived cells cultures and modest enhancement was seen in PF cultures. PGE2 concentration in supernatants from stimulated and unstimulated lymphocyte cultures from PD rabbits were higher than in C and PF cell cultures. These results suggest (a) that under appropriate culture conditions lymphocytes from PD donors are capable of enhanced proliferation and (b) that depressed T cell mitogenesis observed in protein malnutrition may reflect alterations in immunoregulatory signals. The role of interleukin 1 (IL-1) and PGE2 in the modulation of this response is discussed.

Animals↗
PubMed1985

Left ventricular geometry during positive end-expiratory pressure in dogs.

We evaluated changes in left ventricular (LV) geometry in ten dogs during intermittent positive-pressure ventilation (IPPV) with and without 10 cm H2O of positive end-expiratory pressure (PEEP). The dimensions during expiration and inspiration decreased in all three orthogonal axes during PEEP, consistent with decreased LV end-diastolic (ED) and end-systolic (ES) volumes. Within a respiratory cycle, the anterior-posterior (AP) ED dimension during inspiration increased with IPPV alone but decreased when PEEP was added, consistent with presumed differences in pulmonary venous return. This caused opposite changes in AP percent regional shortening. Septal-lateral free wall (SL) percent regional shortening decreased during inspiration with both IPPV and PEEP, but the respiratory variation was significantly less during PEEP. Thus, PEEP did not simply produce a smaller version of the same events seen during IPPV alone. The larger decreases with PEEP observed in ED compared to ES dimensions in the AP and SL axes suggest a dominant regional preload effect, whereas the larger fall in the long axis ES compared to ED dimension suggests a primary regional decrease in afterload. Measurements of the right ventricular SL axis in three dogs showed an overall reduction with PEEP, with the inspiratory dimensions being minimal during both IPPV alone and with PEEP. Thus, ventricular interdependence cannot account for the diminished LV SL dimension with PEEP during any part of the respiratory cycle. These findings suggest that the motion of the LV free wall influenced by changes in lung volume may be at least as important as septal motion in determining LV geometry with PEEP.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Pleural effusions: meeting the diagnostic challenge.

Etiologies of complicated pleural effusions include infections, malignancies, and rheumatologic disorders. Appropriate diagnostic studies are determined by specific clinical situations. Possible causes of benign pleural effusions should be considered first. Commonly overlooked diagnoses include chronic effusions initially due to transudative processes, benign asbestos effusions, and traumatic effusions.

Aged↗
PubMed1984

The putative molybdate-stabilized progesterone receptor subunit is not a steroid-binding protein.

Several reports have appeared recently which contradict our earlier findings on the identity and characterization of chick progesterone receptor. Puri et al. (Puri, R. K., Grandics, P., Dougherty, J. J., and Toft, D. O. (1982) J. Biol. Chem. 257, 10831-10837) have isolated a protein with a molecular weight of Mr approximately 88,000 and have reported that this protein is the "nontransformed" molybdate-stabilized receptor. Because of this discrepancy from our own work, we have repeated their methods and obtained purified samples of this protein. In this paper we show that the Mr = 88,000 +/- 2,000 protein is not a receptor but is apparently an artifact of the use of particular steroid affinity resins. Evidence presented to show that this protein is not the authentic receptor include: 1) it is obtained from affinity resins in 10-fold molar excess over the mass of authentic receptor; 2) its tryptic map does not resemble either authentic receptor subunit; 3) it can be resolved from authentic hormone-binding receptors on DEAE-Sephadex A-25 chromatography; 4) the protein does not bind progesterone; and finally 5) its elution from affinity matrices is not biospecific for progesterone and can even be eluted in equivalent yields with buffer alone. We conclude that the Mr = 88,000 protein is not a progesterone-binding protein.

Animals↗
PubMed1984

Major hemorrhage following administration of intrapleural streptokinase.

Severe spontaneous bleeding has not been reported to complicate therapy with intrapleural streptokinase (SK). Recent data have demonstrated intrapleural SK to be devoid of systemic fibrinolytic effect. This report presents a patient who suffered major hemorrhage following the administration of 500,000 units of SK intrapleurally.

Adult↗
PubMed1983

Mycobacterium simiae. Clinical features and follow-up of twenty-four patients.

The charts of twenty-four patients from whom Mycobacterium simiae was isolated from the sputum were reviewed and the patients seen in follow-up examination when possible. They were divided into 3 groups: 2 patients were felt to have had definite infection with M. simiae, 3 were felt to have had probable infection, and 19 showed no evidence of infection during follow-up for as long as 6 yr. All patients in the study had underlying pulmonary abnormalities. The results of PPD skin tests were negative in patients without evidence of tuberculosis. The patients without evidence of M. simiae infection were found to have had negative initial Acid Fast Bacillus smears, fewer sputum cultures positive for M. simiae, and lighter yields from cultures of M. simiae compared with those in the patients with M. simiae infection. We conclude that M. simiae is a nontuberculous mycobacterium capable of causing progressive granulomatous lung infection, but that it may also be identified as a causal isolate from the sputum of susceptible persons. Antituberculosis chemotherapy should not be employed in this latter group.

Aged↗
PubMed1983

Multiple organ system failure and infection in adult respiratory distress syndrome.

Patients with the adult respiratory distress syndrome and multiple organ system failure have a high mortality rate despite extensive supportive therapy. We evaluated the role of multiple organ system failure and infection in 37 consecutive survivors of the syndrome, and 47 consecutive nonsurvivors on whom autopsies were done. Failure of the central nervous, coagulation, endocrine, gastrointestinal, and renal systems was common in all patients but was more frequent in those who died. Major infections occurred in 46 nonsurvivors and 22 survivors. All patients with bacteremia who had a clinically identified site of infection survived, whereas all patients with bacteremia without a clinically identified site of infection died. Autopsy results of the latter group showed infections requiring surgical drainage for complete therapy. Patients clinically septic but without bacteremia and without a clear site of infection were shown at autopsy to have pneumonia. Multiple organ system failure was more common in infected (93%) than noninfected (47%) patients. Vigorous evaluation and treatment of infection in patients with the adult respiratory distress syndrome may improve survival.

Autopsy↗